Wish I had put more emphasis on cables earlier

With regards to power cords? How relevant can it be if the a.c. wire from my home fuse box to the outlet is not thick?  Would the amp be most affected by the power cord upgrade? Other than that and my dac, can't change the power cord. 

I take it you're just a BIT resistant to advice on cables? How long do you want to take to figure out power cords?  Five years? Ten years before you try?  :(
EVERY power cord is critical!

Yeah. Hate going down slippery slope since this hobby can get really expensive. Haven't really shopped for power cords but are there some reasonably priced ones worth recommending?

@OP,
I, too, was skeptical about power cords. I just bought inexpensive Zu cables and called it a day.
Then I listened to the new AQ cables-speaker, interconnect and power- and became a believer in what cables can do to a system.
Unfortunately, they can become costly.
Though it depends upon your equipment, and budget, I would recommend Audioquest Thunder power cords. They are the least expensive of the newest bunch released and will give you a taste of what a PC can do. They are popping up used nowadays, but I will say these cables are a bit unwieldy, so be sure to add additional length as well as some right angle connectors.
Bob

Wow. Maybe I can get in before the naysayers make the thread worthless. I was skeptical as most are. Especially about PC. But I've come to understand that everything counts. One mistake I may have made early on when I bought my cables is putting a lot of silver in my system. That was 15 yrs ago. And just lately I was reminded of that and its  possibility of causing me to have to fight brightness in my system. My general motto is that anything worth doing is worth doing to excess. So all silver wires is what I ended up with. Now I'm considering "Audio Envy" cables which are supposedly some giant killers. 45 day return and reasonable cost. Great reviews. They will be my next cable adventure. Oh BTW PCs are copper and they made a difference worthy of their cost or more.